Wheelhop, excessive body roll, and tire spin are all the result of overpowering a factory coil or leaf-spring rear suspension system. Control is what gains traction, and traction leads to faster acceleration and stability during high-speed cornering. While the factory leaf-spring suspension systems on many early Chevy muscle cars worked well for the era, suspension has evolved, making the original stuff sorely dated.

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Using our F73 Camaro as an example, we wanted it to accelerate hard and take corners at greater speeds. We wanted a suspension system that's strong enough for racing yet comfortable during normal street use.

Asking for the world? Sure, but thanks to Detroit Speed we can have it. We're talking about its QUADRALink system that's completely tunable and designed specifically for '70-81 Camaros. This package features an adjustable track bar, upper and lower control arms, and optional coilover shocks that allow you to upgrade from the factory leaf-spring setup. The coilover shocks feature a custom valving for the ultimate performance and ride quality, including ride height adjustability. Overall, it's a truly one of the best setups we've seen for this chassis.

While the system is intricately detailed and well thought out, it does require careful measuring, cutting, welding, and grinding. So it's not a bad idea to enlist the help of someone with the proper tools and know-how. We turned to the crew at A&E Motorsports, who have been handling F73s since the beginning.

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It's only a matter of time before our second-gen is ready to hit the streets. With our Detroit Speed suspension complete, we'll follow up this segment with the Moser 9-inch details and start putting the drivetrain and sheetmetal back together. Stay tuned-this is going to be one wild ride!

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F73 QUADRALink Rear Suspension Installation - Four-Way Connection

The Detroit Speed QUADRALink suspension replaces the factory leaf springs with an adjustable four-link-style suspension system, which includes a track bar, upper and lower control arms, and all the mounting hardware.

To help with the install, Detroit Speed includes paper templates used to trace sections of the frame and body that need to be cut out, namely the metal braces for the upper control arm mounting brackets, track bar, and shock mounts.

Knowing that we had a straight unibody and subframe, A&E removed the gas tank, rear axle assembly, and leaf springs, following the instructions. It's the added details that make this kit ideal for builders like A&E or a very experienced home mechanic to install.

The shocks, leaf springs, and axlehousing were unbolted and removed. The kit uses the factory front leaf-spring mounts, so these were cleaned and painted.

This area of the unibody will also be trimmed to make room for the lower control arm bracket.

To make room for the lower control arm, a portion of the factory subframe needs to be cut away and later boxed in to strengthen the area.

On the upper portion of the rear subframe, an area is cut out to make room for the top shock mount.

This template is used for making a square hole in the Camaro's floor, just behind the passenger seat, to provide room for the upper control arm mounting pocket. Note: The instructions also show how to modify the rear seat frame.

All the areas that needed to be trimmed were carefully measured, scribed, and marked. Because unibody cars can twist and the subframe and body could be out of alignment, A&E checked to make sure the Camaro was straight before making any cuts into the frame.

Using a cutting wheel in some areas and a Sawzall in others, we cut away sections of the subframe and floor.

Here you can see an example of the section of subframe that was removed and will be boxed in with an inverted piece of sheetmetal. This adds clearance for the lower control arm to articulate without hitting the subframe.

The Detroit Speed pieces are made slightly oversized so that they can be trimmed to fit perfectly and welded into place. Many of the pieces require welding around the edges, boxing in, and additional spot welding on both sides of the sheetmetal to ensure a strong bond. Triangulation plates and gussets are also included in the kit, ensuring each section is much stronger than the factory frame and thus able to hold up to some high-horsepower launches.

Other areas of the body were cut out with a Sawzall. This section will make room for the wide spring pocket bracket that will support the lower control arm.

The bracket for the lower control arm requires a bit of room. There's a lot of cutting here, but the heavy-duty brace will actually strengthen the area.

Looking down into the back-seat floorboard, you can see the areas that were cut away.

With several of the pieces tacked and welded into position, you can see how it boxed in the rear subframe area.

The upper control arm mount pocket is mocked into position and holes are cut along the outer portion of the area. This allows the outer mounting plate to be spot-welded from inside the floorboard as well as around the outside of the plate.

From the inside, this is how the control arm pocket fit into position. That reinforcement plate will be spot-welded to strengthen the area.

The upper control arm pocket and upper framerail doubler is a single piece that's also spot-welded along the frame, which includes gussets and added support for the top shock mount.

A triangulation bracket provides extra strength to these areas.

A close-up of the brace where the shock mount is located shows how the wider brace is welded to the original subframe. What you can't see are the small pieces at the top of the bracket that fully box in the area. Once the welding is complete, the welds are ground down for a smooth finish.

To help locate the track bar, a transverse tube must be welded to the top of the assembly. A&E carefully measured, trimmed, and welded it in place. Two L-brackets also secure it to the floorboard.

The Camaro's original leaf-spring mounts are reused. They're bolted to the new spring pocket bracket assembly (shown tacked in place here) that provides a much stronger structure.

Detroit Speed's control arms feature rubber bushings and the company's Swivel-Links that allow the endlinks to pivot, eliminating binding and excessive load on the jam nuts.

The lower control arms are mounted to the leaf-spring mounts with a spacer. From there, the mounts are then bolted into the Detroit Speed spring pocket assembly on the frame.

We also opted for a Moser 9-inch housing to which Detroit Speed added its bracket assembly for the track bar, control arms, and shock mounts.

Since we were trial-fitting the system, we didn't tighten any of the control arm bolts just yet. These need to be tightened with the rear axle at ride height to avoid any binding of the bushings.

Detroit Speed offers a number of shocks for various needs, including double-adjustable aluminum coilovers that allow you to adjust both the compression and rebound. We opted to stay with the lightweight aluminum coilovers included in the package, which feature their own custom valving.

Once all the cutting, welding, and grinding was complete, A&E assembled the suspension components to see how it all fit. Because the system is fully adjustable, there's no limit to how well this rear suspension can be tuned. The control arms can be adjusted for optimum pinion angle to improve drag racing launches. The track bar (Panhard rod) can also be adjusted to provide minimum side-to-side movement of the rear axle. The next step is to wait for our Moser axles and differential to arrive. From there we'll install the Baer disc brakes and have a rolling chassis again.

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